The present invention relates to an article transfer apparatus used in cartoning machines, etc., which is adapted to carry articles by holding them on both their front- and rear-end sides by means of hooks.
Recently, in the field of encasing work as in a confectionery, etc., cartoning machines have been used which fold unerected cartons as they carry them, and which tuck in and paste up the margin flaps of the cartons after they are loaded. FIG. 1 is a perspective view of an article transfer apparatus used in one such cartoning machine. This apparatus uses four hooks in the front and in the rear to prevent the article from being dislocated during various intermediate operations, such as tucking, etc. The driving force of a motor 10 rotating in the counterclockwise direction is transmitted to a driving shaft 14 of a conveyor means by means of a chain 12. Driving sprockets 16a and 16b are fixedly mounted on the driving shaft 14, while driving sprockets 16c and 16d are rotatably fitted on the shaft 14. The driving sprockets 16c and 16d are joined to the driving sprockets 16a and 16b, respectively, by means of bolts 18. The driving sprockets 16a, 16b, 16c and 16d rotate the endless chains in a counterclockwise direction along with the rear-end hooks 20a and 20b, and the front-end hooks 20c and 20d, respectively, and carry an article between the hooks 20c, 20d and 20a, 20b in the direction of arrow A. Although only one set of hooks 20a to 20d is shown in FIG. 1, a plurality of sets of hooks are actually provided so that a plurality of articles are on the path of transfer at a time.
In the prior art article transfer apparatus, if the articles to be transferred are varied in size, then the distance W between the front- and rear-end hooks must be changed. In doing this, the position of the front-end hooks 20c and 20d needs to be shifted by rotating the driving sprockets 16c and 16d relative to the driving sprockets 16a and 16b after removing the bolts 18. As this adjustment work is manual, it takes a lot of time and is not very accurate. Even though the front-end hooks can be shifted with high accuracy, tightening the bolts will sometimes lower the positioning accuracy.